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mg backfire dcoe

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It's apparently leaning out under acceleration.

If you're intrepid enough to own this car, you likely posess the mechanical aptitude to work this through. We need to get you a book first then. I've TOMES on Webers here, but don't know what is available these days. First we need feedback from those who've recently gone seeking Weber info. The web and Google are your friends, too. Familiarity with DCOE internals and the nomenclature are the first order of business.
 
Pat Braden's book on Weber carbs is available and is quite good, IMHO. It does a good job of explaining how these carbs operate and the basics of tuning them. It also has a very good step-by-step rebuild chapter - with a number of good photographs.
 
Marc, in stock trim, a 1275 puts out about 62 HP, at the flywheel.
A reasonable starting point for a DCOE 45 on a stock 1275 would be:
Choke tube: 34MM
Main jet: 140
Air correction jet: 200
Emulsion tube: 5
Pump Jet: 40
Idle Jet: 55
Auxiliary Venturi: 4.5

Jeff
 
[ QUOTE ]
Pat Braden's book on Weber carbs is available and is quite good, IMHO. It does a good job of explaining how these carbs operate and the basics of tuning them. It also has a very good step-by-step rebuild chapter - with a number of good photographs.

[/ QUOTE ]

Now we're "off to the races"! Marc, find that and do a bit of reading/study and see what you can come up with? And again I'll say: Float level has a LOT to do with the way these carbs behave. IIRC the 45 mated to a BMC will want a 10mm float height. Good place to start.

EDIT: I see there's NO choke cable connected. Make CERTAIN the choke linkage is held in the "off" position. A garbage bag wire tie is sufficient, it doesn't want to be *forced* into place just held in place.
 
well i guess its time i bring this one back from the dead im looking into getting new jets and such for my DCOE to make my midgy run better the thing is that in all of my asking around i keep getting different answers as to what jets and such i need. so if anyone actually has a DCOE on there 1275 id like to know what its jetted at....... and yes its a stock 1275 no upgrades

currently it is jetted: DCOE 45

Choke tube: 37MM
Main jet: 140
Air correction jet: 180
Emulsion tube: F2
Pump Jet: 55
Idle Jet: 50/F2
Auxiliary Venturi: 4.5
 
Choke tubes and air correctors as a 'first step'. Use Jeff's post above as reference. And keep in mind he said: "A reasonable starting point..."

Most immediate change needs to be that honkin' great 37MM hole. That's more like the setup for an 1800/2000.
 
Seems it to me, but I haven't gone Weber bits shopping in a few years.

Other opinions?
 
teglerizer.com has a very good writeup on this.

From what I see on your specs, I would recommend smaller throat, 34 instead of 37, richer idle jet,(too often to compensate for lean idle the speed gets raised so you're "starting" from off idle) And leaner main fuel(air jet would be what I recommend changing.

Pierce Manifolds, in California, several Weber dealers on the East Coast(google Weber carburetor parts) carry most parts.
 
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